1. Field of the Invention
This invention relates to a protective cover for a flexible joint such as an automotive ball joint.
2. Disclosure Information
Flexible joints are used in a variety of vehicles and other types of mechanisms. One commonly employed type of flexible joint is the so-called ball joint in which a stud having a spherical or semispherical head at one end protrudes from a socket which is mounted to a linkage or to some other movable component. The ball and socket are protected from internal contamination by means of a flexible boot seal which is fixed to the stud and to the socket. Such ball joints are commonly used in the suspensions and steering linkages of automotive vehicles and have been so used for decades.
For a long period following initial employment of ball joints in automotive vehicles, such joints were commonly provided with grease fittings allowing the joint to be lubricated periodically so as to prolong the life of the joint. In recent years, however, the trend has been, at least in the automotive industry, toward provision of suspension and steering joints which do not require periodic maintenance. Such joints do, however, require sealing structures having sufficient integrity to exclude environmental contamination from the joint, it being understood by those skilled in the art that environmental contamination will quickly cause failure of an otherwise sound joint.
It has been determined that automotive ball joints of the type used for steering and suspension linkages frequently fail due to damage incurred by the seal during the processing and subsequent shipping of the joints and of the components or subassemblies into which the joints are assembled.
The processing of ball joints and suspension control arms employing such joints usually involves several steps. In the first step, the ball joint itself is assembled and then stored for an indeterminate period of time, during which time the ball joint may be shipped to another location prior to assembly into a control arm. During the initial storage and shipping of the ball joint, the joints are usually stored in bins. This storage presents an opportunity for the boot seal of the ball joint to be cut or torn by the threaded studs protruding from other ball joints contained in the same bin. In the event that the ball joint survives the initial shipping and handling with the boot seal element intact, yet other opportunities exist for the seal to be damaged. For example, after installation of the ball joint into a suspension control arm, the arm assemblies will be placed in other bins or baskets and moved to the vehicle assembly plant. During the subsequent shipping and handling further opportunity exists for the ball joint boot seals to become damaged because the seals may be cut or abraded by the stud portions of the ball joints themselves or by sharp edges formed on the control arms, which may weigh 15-20 lbs, or more.
The boot seal is not the only element of the ball joint which is susceptible to shipping and handling damage. U.S. Pat. Nos. 3,199,902 and 3,598,434 disclose protective devices intended to prevent damage to the threads of ball joints while at the same time retaining a seal upon the joint. Although the protectors disclosed in these patents will protect the ball joints' threads from damage, neither serves to protect the seal from damage during shipping and handling prior to installation of the ball joint upon a vehicle. U.S. Pat. No. 4,552,480 discloses a ball socket and member having a skirt at its open end which is adapted to form a seal with a member carrying the ball so as to prevent leakage or contamination of lubricant contained within the body cavity. No mechanism is disclosed, however, in the '480 patent for protecting the skirt from damage.
It is known in the prior art to provide a protective cover for a flexible joint in which the cover comprises two tubular sections without either a flexible skirt depending from the larger of the two tubular sections as shown in the present invention, and further without having a stop abutment plug situated within the protective cover for the purpose of controlling the extent to which the cover is engaged upon the ball joint or other flexible joint. The importance of these features will be explained in this specification.
It is an object of the present invention to provide a protective cover for a flexible joint, such as an automotive ball joint, which will prevent damage to the threaded portion of the ball joint stud while protecting the joint's boot seal, not only after the ball joint is assembled, but also after a control arm assembly or other component including the ball joint has been assembled.
It is a further object of the present invention to provide a protective cover for a flexible joint which is compatible with current systems employed for inserting ball joints into control arms.
It is an advantage of the present invention that the present protective cover for a flexible joint will protect such a joint even if the joint is rotated or knocked to an off-center position.
It is an advantage of the present invention that a protective cover for a flexible joint according to this invention will prevent damage to both the threaded and boot seal portions of the ball joint, both before and after the ball joint is installed into a vehicle control arm, and indeed at all times until the control arm itself has been installed in a vehicle.
It is a further advantage of the present invention that a protective cover for a flexible joint according to this invention may be easily employed during the production process.
Other objects, features and advantages of the Present invention will become apparent to the reader of this specification.